I'm a dyed-in-the-wool free-roundtripper at the most frugal award level possible. I'll also comb the fine-print rules on stopovers and open jaws, research the routings on the Net and milk that for the most destinations possible (within a tight budget).

For example, I took AMS as a 5-day stopover on an ATL-BKK routing via the Atlantic, and also got a non-stopover stopover (i.e. less than 24 hours) in Singapore.

I really like upgrades (since I get them free often in the U.S.) but still can't bring myself to spend a lot of miles on them.